1. Field of the Invention
The present invention relates to an image-forming device that forms color images by composing a plurality of different color materials.
2. Description of Related Art
Japanese unexamined patent application publication No. 2001-218074 has proposed an image-forming device that forms gray by composing toner of different colors, such as magenta (M), cyan (C), and yellow (Y).
This image-forming device refers to density adjustment data, which gives the amount of each color material needed to form gray at various densities, in order to determine what amounts of the three color toners should be used.
When forming gray, it is necessary to maintain a balance among the amounts of the three composed colors. This is because if the composed amounts vary, the result will not become a suitable achromatic gray. The above-described image-forming device therefore corrects the density adjustment data based on shift amounts x, y, and z for the three colors at various gradation levels between scanned values of the three colors and scanned values of gray.